1. Field of the Invention
The present invention relates to brake devices for an automobile or the like. More particularly, the present invention relates to a wet-type brake device in which a frictional force generated within the brake is fed back to a cam lever to help operate the brake.
2. Description of the Prior Art
Prior art brake devices which utilize the frictional force generated between a plurality of stators and rotors within the brake to assist in turning a cam-mounted pressure plate towards the rotors are known, as is disclosed in unexamined Japanese Utility Model Application Publication No. 55-80542 and Japanese Utility Model Publication No. 60-15004.
In such devices, the servo function obtained by feeding the frictional force generated between the rotors and stators back to the pressure plate was generated only by the rotor which is located at the outermost position adjacent to the pressure plate, making it impossible to adjust the servo force being fed back to the pressure plate.
In addition, the rotors in such prior art devices exerted an impacting sliding force onto the pressure plate at the moment the brake was operated. This force was frequently transmitted back through the baking linkage to the vehicle operator, thus reducing the life of the system and causing discomfort to the operator.
Moreover, a further problem that was common to such prior art devices was that the above-described servo mechanism would actually create a negative feedback when the vehicle was in reverse, thereby reducing the braking force that could be applied to the rotors. This resulted because the frictional force generated between the rotors and the stators would actually cause the pressure plate to be forced in a direction opposite to its braking position.